Electrical devices such as breaker boxes, electrical control boxes, and battery systems employ a cover plate with a mechanical locking mechanism that is arranged to engage a power switch when locked and disengage the power switch when unlocked. A common safety feature for breaker boxes or control boxes is a mechanical locking mechanism that is engaged whenever a main power switch is turned on. In one embodiment, the power switch removes contacts from a power feed side, thus isolating or removing power from the load side of the switch and all the circuitry connected to the load side of the switch. The power switch serves a dual purpose, including removing power from the feed side and disengaging a mechanical lock that prevents access to the feed or load contacts when the power switch is disengaged. When the switch is opened and thus disengaged the mechanical lock is also disengaged allowing access to the contacts. Residual electric power in a breaker box may not be discharged when the power switch is turned off, with such residual power caused by secondary power feeds such as a separate electric power line, by a mis-wired system, or by a DC power line.
Transformable materials, such as shape memory alloys (SMAs) have one or more properties that can be changed in a controlled fashion by external stimuli, such as temperature, electric field, stress, magnetic field, or pH level. Common smart materials include piezoelectric materials, shape-memory alloys, shape-memory polymers, magnetostrictive materials, magnetic shape-memory alloys, pH-sensitive polymers, temperature-responsive polymers, and chromic materials.
A shape-memory alloy is a metal alloy that remembers a cold-forged shape. This shape may also be referred to as an original, initial, or permanent state. The alloy, if deformed from its original shape by an applied load will return to it, i.e., will exhibit a shape memory in response to being exposed to an input of heat or electric current. Shape-memory alloys may be commonly known by names including the following: SMA, smart metal, memory metal, memory alloy, muscle wire, and smart alloy.
Transformable materials are referred to herein mostly as smart materials for ease of description. Any use of the term “smart material” is not intended to limit the material to being a certain type of transformable material, and references herein to smart materials should be considered to include broader readings whereby the material can be a transformable material other than what might be considered as only a smart material.